Power cable daisy chains are systems where multiple cables connect in a chain-like arrangement.
Power cable daisy chains are systems where multiple cables connect in a chain-like arrangement.
Hello, welcome! Since you're new to building, it's good to know which cable to connect to the components. For your PSU, you should use one of the two cables in the chain—either labeled 1 or 2. You can connect both at the same time if needed. Don't worry about PCIe or EPS cables; just focus on matching the correct ones.
Typically the EPS side connects to the PSU while the other side goes to the CPU. The cable shown in the second image is for SATA power. All components operate simultaneously, and because SSDs use only 5-10 watts when fully loaded, it's not a concern as they won't be overloaded by being completely filled.
Typically, the end connector is placed at the end of the longest wire into the power supply—since the two 8-pin connectors are closer together, they fit in the motherboard’s tight spots. This connection leads into the PSU—first connector (best suited for EPS 8-pin) followed by a second one (optional, could switch to a 4-pin if it splits into two 4-pin sections or another 8-pin EPS). I wouldn’t use both connectors on the same cable, as it would be unnecessary.
The purpose of having two 8-pin EPS connectors is to increase the number of wires linking the PSU and the motherboard. This distributes power more evenly, reducing losses, minimizing heat buildup, and lessening stress on connector contacts.
With a cable like this, you maintain the same wire count between the PSU and motherboard (8 wires in 4 pairs), so you miss out on those advantages. Modern processors use less power—Ryzen 5600X draws about 80W, while a 12th-gen Intel processor can hit 160W or more when overclocked. Even the 16-core 5950X stays under 200W.
The 8-pin EPS and CPU connectors are built to handle more current safely. Each connector’s pins/contacts can manage at least 9A, and some supplies use up to 13A. Exceeding this can cause overheating, melting, or damage—especially with the 12th-gen Intel chips that boost to high frequencies.
Current limits mainly come from the connector contacts and cable capacity. The individual pins are rated for around 9A, but some supplies go higher. The actual power delivered to the CPU is constrained by how much current the contacts and cables can safely carry.
Physical wires can handle several amps—typically around 10A per pair—thanks to short lengths (about a meter). Manufacturers design these ratings to prevent overheating, voltage drops, and physical failure.
For instance, a standard AWG18 wire has roughly 0.021 ohms per meter. At 120W and 10A, the voltage drop would be about 0.4V, and power loss would be around 4.2W. With just two wires, the voltage across them drops to ~11.6V, and the CPU would experience less heat.
Using four pairs spreads the current—each pair handling only 2.5A—reducing voltage loss to ~0.1V and power dissipation to just 0.13W per pair. This approach optimizes efficiency and protects components.
I usually choose the shortest plug when it works, since it suggests less cable loss. But for actual cable lengths that matter, it's almost insignificant. When you need two plugs, using the PSU's cables is better—especially if it has two, otherwise just use the plug on the cable. If it wouldn't work with one plug, the second one wouldn't exist at all.
It's acceptable, though still not useful. We assume the CPU uses 200 watts with a single EPS 8 pin, while the other connector remains unused [psu] ========== 200 watts ========= [8 pin EPS: 200w] ===== [unused] One connector is left idle [8 pin EPS: 100w] ===*=== [8 pin EPS: 100w] || [psu] ========== 200 watts ========= // Identical output of 200 watts between psu and connectors, no advantage. Only the two physical connectors on the motherboard gain a slight cooling benefit but result in a less organized setup. Two cables used: [8 pin EPS: 100w] ==// [8 pin EPS: 100w] || [psu] ========== 100 watts ========= // This arrangement makes sense when minimizing voltage drops, cooling, etc., but if the CPU uses under 150 watts, using a second connector adds little value.
When the card features two connectors, you connect two items. The remaining points are irrelevant.